Technical and Economic Viability of Corn with Azospirillum brasilense Associated with Acidity Correctives and Nitrogen

Abstract

There is a lack of more comprehensive research defining how much mineral N can be applied as regards the efficiency of BNF to attain high with Azospirillum brasilense, what is a bacterium that stands out for its biological nitrogen fixation (BNF) in corn crops, reaching economically sustainable yields. Moreover, it would be interesting to investigate the use of silicon, which exerts numerous benefits on grasses, especially when the plants are subjected to biotic and abiotic stresses. The aim of this work was to study a synergistic effect between the inoculation with A. brasilense and the application of silicon, thus enabling a higher efficiency of nitrogen fertilization, evaluating the grain yield of irrigated corn in economic terms. The experiment was conducted in Selvíria, MS, Brazil, under a no-till system, on a Latossolo Vermelho distrófico (Oxisol). The experiment was set up as a randomized block design with four replications, in a 2 × 5 × 2 factorial arrangement consisting of two soil corrective sources (dolomitic limestone and Ca and Mg silicate as source of Si); five doses of N (0, 50, 100, 150 and 200 kg ha -1 ); with and without inoculation with A. brasilense. The inoculation makes the corn increase much more profitable, irrespective of N doses and corrective source. The N dose of 200 kg ha -1 with dolomitic limestone, associated with inoculation provided greater grain yield. However, the highest economic return was obtained at the N dose of 100 kg ha -1 , with dolomitic limestone application and inoculation.

Corn Yield and Phosphorus Use Efficiency Response to Phosphorus Rates Associated With Plant Growth Promoting Bacteria

“…The use of agroecological practices such as inoculation by plant growth-promoting bacteria (PGPB) can represent a sustainable alternative for increase nutrient use efficiency in tropical agriculture (Galindo et al, 2018a(Galindo et al, ,b, 2019aMartins et al, 2018). The use of these PGPB is growing, particularly in Latin America, for different crops (Souza et al, 2015;Martins et al, 2018;Galindo et al, 2019a).…”

Can silicon applied to correct soil acidity in combination with Azospirillum brasilense inoculation improve nitrogen use efficiency in maize?

“…These are commercial strains used in Brazil with brand name AzoTotal 1 . These strains when used under similar conditions (Brazilian Savannah) have shown positive results in maize development [2,8,13,16]. Seeds were inoculated one hour before planting and after seed treatment with fungicide and insecticide when the seeds were completely dry.…”

“…Grass crops, such as maize, wheat (Triticum aestivum) and rice (Oryza sativa), consume approximately 50% of all N-based fertilizer produced [7]. It has been estimated that as much as 15% of the total operating profit of the maize produced in the Brazilian Savannah is due to side-dress N application [8]. It is well known that production and over application of N fertilizer contribute to greenhouse gas emission and water contamination [9][10][11].…”

“…It is well known that production and over application of N fertilizer contribute to greenhouse gas emission and water contamination [9][10][11]. Management practices that improve N use efficiency (NUE) are therefore needed to assure that maize productivity is maximized while reducing the environmental impacts resulting from excessive nutrient application in the Brazilian Savannah [8,12,13].…”

“…The use of biological agents such as plant growth-promoting bacteria (PGPB) can improve NUE, crop development, and grain yield in cereal crops growing in tropical regions [6,8,10]. Several PGPB genera associate with different species of agricultural importance, such as Azospirillum, Arthobacter, Azotobacter, Bacillus, Bradyrhizobium, Burkholderia, Clostridium, Gluconacetobacter, Herbaspirillum, Pseudomonas, Rhizobium and Streptomyces [14].…”